Signal lamp



Dec- 5, 1944- G. w. oNKsEN, JR., ET Ax. 2,364,468

V SIGNAL LAMP Filed Nov. 13, 1941 3 Sheets-Sheet l Snventors De- 5 1944- G. w. oNKsEN, JR., ET AL 2,364,458

S I GNAL LAMP Filed Nov. 13, 1941 3 Sheets-Sheet 2 Bnventors (Ittornegs Dec- 5, 1944- G. w. oNKsEN, JR., ET AL v 2,354,468

r I SIGNAL LAMP 5 Sheets-Sheet 3 Snncntors of l'. marker lamp.-

-ing to our invention Patented Dec. 5, 1944 l AUNITED STATES PATENT ,orsi/cs,

v`George Onksen, v.'ir., Anderson, Ind.. and Clifford C. Duell, Baltimore, Md.; saidV Onksen, Jr.. assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application November 13, 1941, Serial No. 418,898

tz claims, '(01. 11s-.329)

Our invention relates to signal lamps such as are used on military vehicles.

Signal lamps for v military vehicles present problems that are not found in ordinary lamp design. The conditions of modern warfare require that a signal lamp be visible at a, reasonable i distance from the vehicle when the observer is in of somewhere near the plane of operation of that vehicle. The lamp must not, however, be visible y from above except Within limits too close for the safe operation of aircraft, Likewise,v the signal given by the lamp must not be visible at too great an angle to the side. Furthermore, the reduced illumination necessary tc prevent observation from above requires that some means be provided for determination ofthe distance of the observer from the vehicle providedwith the signal lamp. l y

An object of our invention is to provide a signal lamp whichl gives a signal clearly visible to an observer within-a limited distance of the vehicle but not visible toan observer beyond a very limited range above the vehicle. Another object of our invention is to provide .a signalight whichind icates to an observer hcw close heis to the light.

More specifically itis an object of our invention to providev a signal light in which the light is transmitted through a restricted channel which limits visibility' of the signal to smalL--rather well-defined angles of observation. vAlso in our.

Figuren is s dtau'view showing the grouping and spacing of the light openings forming the tail light signal, with representative dimensions,

and Figure 14 is a view illustrating the anglesfof ffor bulbs I6' and I8 to insure against theI light of one bulb interfering with the signal of the other. Each of compartments 22 is provided with a gaslket 2l of any suitable material such as rubber, and having a substantially channel-shaped cross section. Fitting in theend of compartment 22 is signal lamps we provide iadjacent light emitting openings which, together, appear as one light beyond a certain distance frpnlthe signal lamp and which appearas'twolights within a given distance from the lamp. It is thus possible for an v observer to ascertain his'proimity to the signal vobserved, within predetermined ranges. 'f

Figure 1 is an `elevation view of one of our sigi nal lamps adapted' to be used as agear signal.

Figure 2 is a view with parts 'broken-away and in section substantially on line 2-2'01 Flgurell; Figure 3. is an elevation view of another signal lamp inade according to our invention. This lamp likewise. is adapted signal lamp. l f

Figure! is 'a view with parts broken away and lin section substantially on line 4-4 of Figure 3.

tobe used as a rear* l v 45, 48 may be provided to make 4the assembly sublter 2B, the iianges of which are held in the channell of gasket 24. 'Ihis iilter is preferably ma'de of a light pervious material such as glass or any ofthe common molded plastics. The lter may be clear or colored, as desired. The outer face of filter 26 is coated 'with a light impervious or opaque substance 28, such as black paint.

4Coating 28 covers the entire surface except for a generally Y-shaped window 30 in the upper lter 28,through which the stop signal light passes and 'a 'plurality of similar windows 32 in lower filter Figure 5 is an elevation view o f a marker-lamp mada according to our invention be used as a front signal lamp.

Figure B is a view o! the lamp of pamrtsbroken away in section substantially on and adapted to Figure 7 is an elevation viewoi' a modiiication rieures s, 9, .1'0 and 11 .are elevation views or modiiications of rear signal lamps made accord- 4luxure 121s sn elevation viewA of stm another modiilcationofamarke'rlamp.` 'l

rinirsswit'n 28 through which the tail light signal-is emitted. Windows 30 and 32 may be made by masking out the areas `of the indentations at the e that coating 28 is sprayed 4on.l'.enses 38 and 40 of any suitable light transmitting material s'uchas Lucite-may' be provided. lThese lenses may be heldin placeV by alight impervious cover plate 42 which forms an end wall for casing III and completes `the lamp housing.r Cover plate l2 may be secured to casing I 0 byfscrews Il. Another gasket stantially dust proof. We have found it desirable to provide a small opening k48 in casing I0 and a small channelili lat the bottom of cover platel 42 for the purpose of draining any moisture which may condense within the housing or which may possibly leak into the housing from above.

The'slgnallampshowninlilguresii andiis similar tothat of Figures 1 and2 in that thetall light portion of the signal comprising thevlower assembly is the same. However, inl Figures '3 and 4 we provide, instead of the stop light of' Flgures1and2,asimpleiensorglass ilheldin `Place against gasket 54 bythe inwardly turned edges 22a of compartment, 22, and also by cover I2.- Lens I2 may be transparent ortranslucent and it moy be clear or colored os desired. The

structural features of the housings shown in Figlamp having a casing 58 provided with a suitable mounting base il. A light bulb Il is disposed in casing I8. A' cap or cover plate l2 completes the lamp housing. It has secured thereto. asby a rivet Il, a bracket II. the inwardlyturned end oi which engages a recess, such as a notch or slot -A Il near the edge at the top of casing Il. A bracket is secured to the bottom of casing It: this bracket is threaded and is engaged by screw 12 which extends through cover plate 82 to hold the cover in place. A gasket 14 is disposed between cover l2 and casing It. Cover 82 is provided substantially centrally thereof with an extended aperture or walled opening in which are disposed gasket 18, lens 18 of a light pervious material -such as Lucite, and a filter Il. Gasket 18, lens 18 and nlter Il are held in place in the compartment formed by this walled opening between inwardly turned iianges 82 and I8 of the opening through cover plate 82. Here also nlter 8l is coated with an opaque substance Il such as black paint except for generally Y-shapcd windows II which permit the on of light through filter 8l. The structural features oi' the housing shown in Figures 5 and 6 form no part of this invention, but are claimed in the copending application'of John H. Diedring. Signal lamp,`

Serial No. 418,897, illed November 13, 1941.

In Figure 7 we have illustrated a modiiied type of marker. In this modiilcation a clear transparent lens II is held in place by cover plate I2'. A -light impervious screen or plate -having a window 92 is disposed back of lens Il. Window l2 may take the form of an elongated slot jas shown. Spaced from the/light impervious plate is a second plate or disk of light impervious material in which is provided a window Il. Window 8l is aligned with window 82 and the light' source, and is preferably smaller than window 82.

In the modiiled signal lamp of Figure 8, transparent lenses 88 are held in place by cover plate place by cover plate 42' as in Figure 8. How` ever, the nrst light impervious plate has four shorter slots or windows |82 instead of the two,

long slots 80 of Figure 8. As in the lamp oi Figure 8, a second light impervious plate spaced from the first has four small windowsl Ill aligned with windows |l2. Windows |80, however, are smaller than windows |82. The stoplight portion of the lamp in Figure 9 may be similar to that shown in Figures 3 and 4.

In the modification oi' Figure 10 a transparent lens 86 is held in place by cover plate I2' as'A ascuas light source directly or through a colored ii'lter.

The stop lilhtpol'tlOn 0! 818D lamp Il my be similar to that of Figures 3 and 4.

In the modiiication of Figure 11 we have provided a' light impervious cover plate Ill secured by screws Il. Cover plate |08 is provided with 'nou forming windows In and m. m the amp disposed between screen |2l and the light source.

before. The first opaque screen has one long slot or window |84. Spaced fromI this screen is a secong screen having two reshaped slots or windows llt. through which light may pass `from the In the marker lamp modiiication shown in Figure 12. a cover plate |26 is held in place by screws lamp such as a combination tail and stop light shownin Figures 1 and 2, the window( I2 serve .as atail light and window as a stop signal.

It will be found that an observer beyond a predetermined distance from the lamp will see the light emitted through windows sz as though it came from a single window or source instead of from four. As the observer approaches the signal lamp to a distance just within the iirst named predetermined distance but beyond a second predetermined distance lessthan the first, the singie light source appears to divide in two, each of which is made up of two closely spaced windows 82 as seen inFigure 1. As'the observer con tinues to approach the signal, and does so toa point within the second predetermined distance, he sees four separate light sources.

It is thus evident that we have provided a signal lamp which makes it possible for an observer to determine within rather definite ranges what his proximity to the signal is. We have found the following distances satisfactory: four separate sources discernible up to 50-60 feet from the lamp; two sources from there to -180 feet; and one light" source beyond feet trom the signal. In Fig. 13 we have shown a detail view of the tail lamp section of our signal lamp. indicating the grouping and spacing which we have developed to give the above described ranges. The dimensions and spacing for the 'above ranges are the following:

f=1 inch and ing the spacing or size of the windows, or 'the intensity of the light admitted to these windows,l

or any combination of these three.

It mayA also be seen from the drawings how we have solved the problem of restricting visibility of the emitted signal to a predetermined angular these windows and with the windows formed" by lenses I8 and l0 respectively; the light thus transmitted will also be visible to an observer slightly of! 'to one side, or above or below, a line representing a center line of,vor an optical axis through, windows v30 and 38, or windows 32 and 40. However, as the observer's vantage point moves fa'rther and farther from 'this imaginary center line, vertically or horizontally, he will eventually reach a point at which the edge of window I8 or 40 will cut oi! the light :from window 30 or windows I2, respectively. -This cutgoil.' is assisted by the expedient of making one setof windows smaller than the aligned set. Visibility of the signals to observers in aircraft is further restricted by the provision of wedge or Y-shaped windows, as shown at 30 and 32, with the narrow part of the window at the bottom, so that vertical cut-olf begins by cutting out the broad strip of light mst, leaving only the narrow mum altitude for thesate operation of aircraft,

which is here'taken as approximately 4 00 feet. Now, it is possible ior vehicles of the type here involved to operate downhill on a 20%A s1ope,. or

about 11%". This line of travel is represented by une D-B with the vehicle at point a and on the slope DB, it is evidext that the signal must not be visible to an observer above line- C-D. Thiscondition. then, xes the vertical cut-otr.

Itis also possible for these vehicles to operate uphill on a 20% slope, represented by line E-B. If the leading vehicle is descending along slope D-B, and the following vehicle is ascending along slope E-B, and the leading vehicle is near the crest so.that the hill-top does not block the line of sight, it is evident that the tail light of the leading vehicle must be visible to an observer Aat an angle DBE below the longitudinal axis of the vehicle.

'The operation, or effect upon an observer, of the signal lamps shown in Figs. 5 to 12 is substantially the same as that of the lamps shown in Figs. 1 to 4, which is described in detail above.

It may be pointed out here that, inasmuch as the front markers shown in Figs. 5, 6 and l2 have only two windows, instead of four as in the tail lamps of Figs. l to 4, the eiects obtainable are necessarily limited. With front markers such as shown in Figs. 5 and 6, we have obtained sat-v isfactory results by 'spacing windows 85 so that two lights are visible up to 50-60 feet, but beyond that distance these two lights appear as one. Itis evident, of course. that the signal windows of the lamp shown in Figures 5 and 6 are merely one half of the windows of the lamps in Figures 1-4.

We claim: y

1. In combination, an opaque housing, a light therein, a window in one wall of said housing, an opaque screen between the iight and the window and spaced from the window, and a wedge-shaped window in the screen, the wide part of said wedgeshaped window being at the top, whereby visibility of the light leaving the housing is restricted to a determinable angle from the horizontal.

2. In combination, a lamp casing having one wall thereof provided with a relatively narrow, horizontal window, a light source in said casing. an opaque screen between said light source 'and said window and spaced from said window, and

' a relatively restricted window in said screen. said screen window' extending vertically and of less width adjacent its` 'lower end than adjacent its upper end, and said windows being substantially horizontally aligned whereby' visibility of the light rays passing through said windows is restricted to a relatively narrow vertical range.

GEORGE wom, n.

cnmr'onn'anmn 

